Diagnostic testing instrument



FIG. 1 is a top view of a diagnostic testing instrument of our design;

FIG. 2 is a bottom view thereof;

FIG. 3 is a left side view thereof;

FIG. 4 is a right side view thereof;

FIG. 5 is a front view thereof;

FIG. 6 is a rear view thereof;

FIG. 7 is a top front perspective view thereof;

FIG. 8 is a top rear perspective view thereof; and,

FIG. 9 is a bottom rear perspective view thereof.

All broken lines represent portions of the diagnostic testing instrument that form no part of the claimed subject matter. 

CLAIM We claim the ornamental design for a diagnostic testing instrument, as shown and described. 